To determine the characteristics of a magnetic head, the electromagnetic conversion efficiencies including recording efficiency and reproduction efficiency are measured. The measurement is conventionally carried out under actual operating conditions, by recording from the magnetic head to a recording medium, and by using the magnetic head to reproduce a signal from the recording medium.
However, the above method requires a substantial expenditure of time in that it is required to physically place the magnetic recording medium in moving contact with the head and achieve an actual operating condition. Furthermore, the measuring operation must be performed by an operator skilled in this kind of measurement. It has also been difficult to obtain an exact measurement result, since magnetic recording media generally exhibit wide dispersion in their magnetic characteristics, and, because the magnetic recording medium is moved at a high speed relative to the magnetic head, a slight fluctuation in spacing occurs between the magnetic head and the recording medium.